Example usage for org.antlr.v4.runtime.atn PredictionContextCache PredictionContextCache

Introduction

In this page you can find the example usage for org.antlr.v4.runtime.atn PredictionContextCache PredictionContextCache.

Prototype

PredictionContextCache

Source Link

Usage

From source file:com.github.robozonky.strategy.natural.SideEffectFreeParser.java

License:Apache License

private static void modifyInterpreter(final NaturalLanguageStrategyParser p) {
    final int originalSize = p.getInterpreter().decisionToDFA.length;
    final DFA[] emptyDFA = new DFA[originalSize]; // give our own array so the static one isn't used
    final ParserATNSimulator newInterpreter = new ParserATNSimulator(p, p.getATN(), emptyDFA,
            new PredictionContextCache());
    newInterpreter.clearDFA(); // initialize our array so that the parser functions properly
    p.setInterpreter(newInterpreter); // replace the interpreter to bypass all static caches
}

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From source file:com.github.robozonky.strategy.natural.SideEffectFreeParser.java

License:Apache License

private static void modifyInterpreter(final NaturalLanguageStrategyLexer l) {
    final int originalSize = l.getInterpreter().decisionToDFA.length;
    final DFA[] emptyDFA = new DFA[originalSize]; // give our own array so the static one isn't used
    final LexerATNSimulator newInterpreter = new LexerATNSimulator(l, l.getATN(), emptyDFA,
            new PredictionContextCache());
    newInterpreter.clearDFA(); // initialize our array so that the lexer functions properly
    l.setInterpreter(newInterpreter); // replace the interpreter to bypass all static caches
}

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From source file:org.eclipse.titan.designer.parsers.ttcn3parser.TTCN3Analyzer.java

License:Open Source License

/**
 * Parse TTCN-3 file using ANTLR v4//from   w w w.  j a  va2 s  .  c o  m
 * @param aReader file to parse (cannot be null, closes aReader)
 * @param aFileLength file length
 * @param aEclipseFile Eclipse dependent resource file
 */
private void parse(final Reader aReader, final int aFileLength, IFile aEclipseFile) {
    CharStream charStream = new UnbufferedCharStream(aReader);
    Ttcn3Lexer lexer = new Ttcn3Lexer(charStream);

    lexer.setCommentTodo(true);
    lexer.setTokenFactory(new CommonTokenFactory(true));
    lexer.initRootInterval(aFileLength);

    TitanListener lexerListener = new TitanListener();
    // remove ConsoleErrorListener
    lexer.removeErrorListeners();
    lexer.addErrorListener(lexerListener);

    // 1. Previously it was UnbufferedTokenStream(lexer), but it was changed to BufferedTokenStream, because UnbufferedTokenStream seems to be unusable. It is an ANTLR 4 bug.
    // Read this: https://groups.google.com/forum/#!topic/antlr-discussion/gsAu-6d3pKU
    // pr_PatternChunk[StringBuilder builder, boolean[] uni]:
    //   $builder.append($v.text); <-- exception is thrown here: java.lang.UnsupportedOperationException: interval 85..85 not in token buffer window: 86..341
    // 2. Changed from BufferedTokenStream to CommonTokenStream, otherwise tokens with "-> channel(HIDDEN)" are not filtered out in lexer.
    final CommonTokenStream tokenStream = new CommonTokenStream(lexer);

    Ttcn3Parser parser = new Ttcn3Parser(tokenStream);
    parser.setBuildParseTree(false);
    PreprocessedTokenStream preprocessor = null;

    if (aEclipseFile != null && GlobalParser.TTCNPP_EXTENSION.equals(aEclipseFile.getFileExtension())) {
        lexer.setTTCNPP();
        preprocessor = new PreprocessedTokenStream(lexer);
        preprocessor.setActualFile(aEclipseFile);
        if (aEclipseFile.getProject() != null) {
            preprocessor.setMacros(
                    PreprocessorSymbolsOptionsData.getTTCN3PreprocessorDefines(aEclipseFile.getProject()));
        }
        parser = new Ttcn3Parser(preprocessor);
        preprocessor.setActualLexer(lexer);
        preprocessor.setParser(parser);
    }

    if (aEclipseFile != null) {
        lexer.setActualFile(aEclipseFile);
        parser.setActualFile(aEclipseFile);
        parser.setProject(aEclipseFile.getProject());
    }

    parser.setLexer(lexer);
    // remove ConsoleErrorListener
    parser.removeErrorListeners();
    TitanListener parserListener = new TitanListener();
    parser.addErrorListener(parserListener);

    // This is added because of the following ANTLR 4 bug:
    // Memory Leak in PredictionContextCache #499
    // https://github.com/antlr/antlr4/issues/499
    DFA[] decisionToDFA = parser.getInterpreter().decisionToDFA;
    parser.setInterpreter(
            new ParserATNSimulator(parser, parser.getATN(), decisionToDFA, new PredictionContextCache()));

    //try SLL mode
    try {
        parser.getInterpreter().setPredictionMode(PredictionMode.SLL);
        parser.pr_TTCN3File();
        warnings = parser.getWarnings();
        mErrorsStored = lexerListener.getErrorsStored();
        mErrorsStored.addAll(parserListener.getErrorsStored());
    } catch (RecognitionException e) {
        // quit
    }

    if (!warnings.isEmpty() || !mErrorsStored.isEmpty()) {
        //SLL mode might have failed, try LL mode
        try {
            CharStream charStream2 = new UnbufferedCharStream(aReader);
            lexer.setInputStream(charStream2);
            //lexer.reset();
            parser.reset();
            parserListener.reset();
            parser.getInterpreter().setPredictionMode(PredictionMode.LL);
            parser.pr_TTCN3File();
            warnings = parser.getWarnings();
            mErrorsStored = lexerListener.getErrorsStored();
            mErrorsStored.addAll(parserListener.getErrorsStored());
        } catch (RecognitionException e) {

        }
    }

    unsupportedConstructs = parser.getUnsupportedConstructs();
    rootInterval = lexer.getRootInterval();
    actualTtc3Module = parser.getModule();
    if (preprocessor != null) {
        // if the file was preprocessed
        mErrorsStored.addAll(preprocessor.getErrorStorage());
        warnings.addAll(preprocessor.getWarnings());
        unsupportedConstructs.addAll(preprocessor.getUnsupportedConstructs());
        if (actualTtc3Module != null) {
            actualTtc3Module.setIncludedFiles(preprocessor.getIncludedFiles());
            actualTtc3Module.setInactiveCodeLocations(preprocessor.getInactiveCodeLocations());
        }
    }
    //TODO: empty mErrorsStored not to store errors from the previous parse round in case of exception

    try {
        aReader.close();
    } catch (IOException e) {
    }
}

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